Thermostatically-controlled heating element



Sept. 18, 1928. 1,684,544

- L. H. LAMONT THEMOSTATICALLY CONTROLLED HEATING ELEMENT Filed Oct- 2 1925 2 Sheets-Sheet 1 Sept. 18, 1928. 1,684,544

L. H. LAMONT THEMOSTATICALLY CONTROLLED HEATING ELEMENT Filed Oct. 24, 1925 2 Sheets-Sheet 2 Patented Sepals; 192g. 7 I UNlTED STATES PATENT "OFFICE.

LEWIS/H. LAMONT, or OAK rARmILLINoIs.

THEBMOSTATIGALLY-CONTROLLED HEATING ELEMENT.

Application .filed October 24,1925." Serial No. 64,503.

' This invention relates: to means'for initially heatingthe fuel supply for internal combustion engines to assist in starting a cold engine. a c

6' It is an object of thisinvention to provide an improved fuel heating system adapted to initially heat the fuel to approximate summer operating conditions for startinga cold motor.v Itis wellknown that afterstarting 10 ainotor it is a simple matter to maintain summer temperatures within the motor on closure, but the initial starting with cold fuel requires a very much richer carburetor adjustment in winter as compared'with sum- 15 mer. 'Heretofore various'forms of fuel va orizin s stems have been so ested where- U y D in a charge of fuel isheated to such a high point as to cause at leastpartial vaporiza tion, the vapor passing into the manifold to give a richer starting mixture. The dangers inherent'in sucha procedure will. be ap parent. The present invention does not con-- template vaporization of the fuel but relates to bringing the fuel in a carburetor to a tions wherein the fuel willbe'properlyvaporized or atomized by the normal action of the carburetor nozzles.

It is also an object of' this invention to I 80. provide a device of the class described adapt ed to be broughtinto action by the normal fully described.

On the drawings: L Figure 1 is an elevation of adevice embodying the features ofthis invention as applied to a carburetor including the conburetor choke; I 'Fig. 2 is an enlarged longitudinal section through the device; 4

Fig. 3 is a bottom view with the switch compartment cover removed;

temperature approximating summer condi-- illustrated in the drawings and hereinafter trol interconnecting the device with the car Fig. 4 is a section .on the line IVIV of Figure 2; i

Fig. 5 is a section on the line V"V of Figure 2; and a Fig, 6 is an elevation showing the modified hookup of the heating device control- As shown on the drawings:

A carburetor 1.0 is shown in Figure'l for the purpose of illustrating the attachment of and'controlfor the device .of this invention, the carburetor float chamber drain opening being indicated at 11 and the choke lever at 12, a rod 13 extending to a spring returned pull button 14 on an instrument board 15. The switch of the device of this invention is also connected to the pull button 14 by the rod :16 so as tobe actuated in unison with the carburetor choke. A casing 17 is providedwitha fuel chamber 18 having an outlet 18 connected to the carburetor drain 11,,and a switch chamber 19 closed at the bottom by a cover 20. The fuel chamber-18 contains a heating element 21 having a lead-in terminal 22 insulated from the casing, the return lead 23 from the heating element being grounded to the plug 24 on which the heating element is mounted.

The switch mechanism proper is mounted on an insulating base 25 secured within the switch compartment 19 with a space between the insulating base and the bottom of the I fuel compartmentcto provide room for a by low temperature conditions.

Mountedon the lower side of the insulats ing baseare two spaced terminals 27 and 28, the terminal 27 being connected by the wire 29 to the heating element terminal 22 while the second terminal 28 receives the thermostatic metal strip 26 which is .flat against the base 25 When hot; This strip is shown in dotted lines as warped upwardly no I live wire 30 from the source of electrical energy, the return being grounded through the caslng and carburetor. Each terminal 27 and 28 clamps one of a pair of spring switch contacts 31in opposed relationship, I

the blades of the contacts being set at a slight angle to make a forced contact with the bridging member 32 which comprises a. U-shaped bar pivoted at 33 to a support 34 havinglugs 35 bent over to form limiting stops in the'open position of the bridge 32. A spring 36 is secured at one end to'the bend of the bridge 32 the other end being attached to a second U-shaped member 37 which is also pivoted at 33, lugs 38 being provided on the support 34 to limit the outward movement thereof. These two U members together with the spring comprises a snap-over mechanism suddenly actuating the switch bridge when the spring center line passes the axis of the pivots 33, the accelerated motion thus imparted to the bridge on the closing thereof serving to force it between the spring switch contacts which are disposed at a slight angle.

A vertically mounted stirrup 39 of insulating material is guided in a slot 40 of the base 25, holes in the ends of the stirrups receiving lugs l2 struck from the U member 37 so that the stirrup controls the snap-over mechanism. The top of the stirrup rests beneath the end of the thermostatic strip which, when warm, holds the stirrup down so that the switch will be open. If the temperature conditions are such that the thermostatic strip is warped into the position shown in dotted lines in Figure :2, the switch may be manually closed by lifting the stirrup. The switch can be closed at any time even against the action of the flat thermostatic strip but under such circumstances the switch is immediately reopened upon the release of the manual control due to the spring like action of the thermostatic strip when flattened out in response to the designed temperature.

The manual control referred to comprises a bell crank pivoted at 3, one arm of ll which extends under the top of the stirrup. A second arm to is formed to engage between balls of a pull chain 46 connected to the rod 16 previously mentioned. Pulling on this chain will lift the stirrup regardless of the position of the thermostatic strip and will therefore close the switch. A spring arm 4-7 engages a third arm i8 of the bell crank and serves to normally return the bell crank to the position shown in the drawings.

The modified form of Figure (3 relates to connecting the pull chain 46, of the manual control for the switch, to the choke lever 12 through the medium of a spring 49 which permits the thermostatic. strip to maintain the switch open, when the chore is closed above a designed temperature to prevent danger of overheating the fuel in hotweather.

In operation the device of this inventionopen position. On the other hand if the temperature of the fuel is below the desired point the thermostat will be warped upwardly so that when the switchis closed by the operation of the choke it remains closed until the fuel in the carburetor is heated to the desired vpoint, even though the choke button is immediately released.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I therefore do not purpose limiting the patent granted otherwise than necessitated by the prior art.

I claim as my invention:

1. A heating device of the class described comprising an electric heating element and a snap-over switch controlling the current supply therefor, said switch comprising a pair of oppositely extending U members pivoted at a common axis, a spring connecting said U members, insulated terminals adapted to be bridged by one of said members, thermostatic member adapted to mechanically open said switch, and a manual control for closing said switch against the action of the thermostatic member;

2. In a device of the class described, an electric heating element, a switch therefor, a thermostat adapted to open said switch at a predetermined temperature, and a manual control for closing said switch comprising a bell crank one arm of which is adapted to receive a pull chain and another arm of which actuates the switch mechanism in opposition to the thermostat.

In a device of the class described an electric heating element, a switch controlling the same, an insulated member for direct actuation of said switch in either direction,

a thermostat adapted to act in one direct-ion on said insulated member, and a bell crank adapted to act in the opposite direction on said member.

1-. In a device of the class described an electric heating elnnent, a switch controlling the same, an insulated member for direct actuation of said switch in either direction, a thermostat adapted to act in one direction on said insulated member, abell crank adapted to act in the opposite direction on said member, and a yielding connect-ion from said bell crank to the choke valve of a carburetor whereby the switch will be actuated in unison therewith.

In testimony whereof I have hereimto subscribed my name.

LElVIS H. LAMONT. 

